This section is intended to provide background information to facilitate a better understanding of various technologies described herein. As the section's title implies, this is a discussion of related art. That such art is related in no way implies that it is prior art. The related art may or may not be prior art. It should therefore be understood that the statements in this section are to be read in this light, and applicant neither concedes nor acquiesces to the position that any given reference is prior art or analogous prior art.
Seismic exploration may utilize a seismic energy source to generate acoustic signals that propagate into the earth along curved paths and refract and partially reflect off subsurface seismic reflectors (e.g., interfaces between subsurface layers). These propagating signals are recorded by sensors (e.g., receivers or geophones located in seismic units) laid out in a seismic spread covering a region of the earth's surface. The recorded signals may then be processed to yield a seismic survey.
Attenuation effects of the Earth are known to alter the phase and amplitude properties of the seismic wavefield, leading to poor resolution in depth-migrated images in and below highly attenuating regions.
Accordingly, there is a need for methods and computing systems that can employ more effective and accurate methods for properly compensating for the seismic attenuation parameter Q, thereby improving depth-migrated images by correcting phase dispersion. Uncorrected phase dispersion often leads to mis-positioned and unfocused reflectors, and amplitude loss, which diminishes the signal to noise ratio of the image of a subsurface region or other multi-dimensional space.
The above referenced summary section is provided to introduce a selection of concepts that are further described below in the detailed description section. The summary is not intended to identify features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Furthermore, the claimed subject matter is not limited to implementations that solve any or most disadvantages noted in any part of this disclosure. Indeed, the systems, methods, processing procedures, techniques, and workflows disclosed herein may complement or replace conventional methods for identifying, isolating, and/or processing various aspects of seismic signals or other data that is collected from a subsurface region or other multi-dimensional space, including time-lapse seismic data collected in a plurality of surveys.
One embodiment of a method for processing seismic data includes the steps of receiving a wavefield generated by reflections in a subsurface region and recorded by a plurality of seismic receivers and compensating the recorded wavefield for amplitude attenuation. The method further includes modelling a propagation of a source wavefield forward in time, from an initial time-state to a final time-state through an earth model that is representative of the subsurface region, wherein the modelling includes phase and amplitude effects of attenuation and modelling a propagation of the compensated recorded wavefield backward in time from a final time-state to an earlier time-state through the earth model, wherein the subsurface region has an absorption characteristic that dampens the recorded wavefield wherein the modelling includes phase and amplitude effects of attenuation. Furthermore, the method includes a step of rendering an image of the subsurface region based at least in part on the modelled source and the modelled compensated recorded wavefield.
Another embodiment of the presend disclosure includes a non-transitory computer-readable medium storing instructions that, when executed by one or more processors of a computing system, cause the computing system to perform operations, the operations including the steps of compensating the recorded wavefield for amplitude attenuation and modelling a propagation of a source wavefield forward in time, from an initial time-state to a final time-state through an earth model that is representative of the subsurface region, wherein the modelling includes phase and amplitude effects of attenuation. Further included are the steps of modelling a propagation of the compensated recorded wavefield backward in time from a final time-state to an earlier time-state through the earth model, wherein the subsurface region has an absorption characteristic that dampens the recorded wavefield wherein the modelling includes phase and amplitude effects of attenuation and rendering an image of the subsurface region based at least in part on the modelled source and the modelled compensated recorded wavefield.
Yet another embodiment of the present disclosure includes a computing system including one or more processors and a memory system comprising one or more non-transitory computer-readable media storing instructions that, when executed by at least one of the one or more processors, cause the computing system to perform operations, the operations including the steps of compensating the recorded wavefield for amplitude attenuation and modelling a propagation of a source wavefield forward in time, from an initial time-state to a final time-state through an earth model that is representative of the subsurface region, wherein the modelling includes phase and amplitude effects of attenuation. The operations include the further steps of modelling a propagation of the compensated recorded wavefield backward in time from a final time-state to an earlier time-state through the earth model, wherein the subsurface region has an absorption characteristic that dampens the recorded wavefield wherein the modelling includes phase and amplitude effects of attenuation and rendering an image of the subsurface region based at least in part on the modelled source and the modelled compensated recorded wavefield.
Another embodiment of the present disclosure includes a method for processing seismic data having the steps of receiving a wavefield generated by reflections in a subsurface region and recorded by a plurality of seismic receivers, compensating the recorded wavefield for amplitude attenuation and modelling a propagation of a source wavefield forward in time, from an initial time-state to a final time-state through an earth model that is representative of the subsurface region, wherein the modelling includes phase and amplitude effects of attenuation. The method further includes the steps of modelling a propagation of the compensated recorded wavefield backward in time from a final time-state to an earlier time-state through the earth model, wherein the subsurface region has an absorption characteristic that dampens the recorded wavefield wherein the modelling includes phase and amplitude effects of attenuation, applying a post migration amplitude compensation to the recorded wavefield, and rendering an image of the subsurface region based at least in part on the modelled source and the modelled compensated recorded wavefields.